Calcineurin promotes adaptation to chronic stress through two distinct mechanisms

• Published in: Molecular biology of the cell 2024-10, Vol.35 (10), p.ar123
• Main Authors: Flynn, Mackenzie J, Harper, Nicholas W, Li, Rui, Zhu, Lihua Julie, Lee, Michael J, Benanti, Jennifer A
• Format: Article
• Language: English
• Subjects: Adaptation, Physiological - physiology; Calcineurin - metabolism; Calcium Chloride - pharmacology; Cell Cycle; DNA-Binding Proteins; Gene Expression Regulation, Fungal; Mitochondria - metabolism; Reactive Oxygen Species - metabolism; Saccharomyces cerevisiae - metabolism; Saccharomyces cerevisiae Proteins - genetics; Saccharomyces cerevisiae Proteins - metabolism; Stress, Physiological; Transcription Factors - metabolism
• ISSN: 1059-1524; 1939-4586; 1939-4586
• DOI: 10.1091/mbc.E24-03-0122

Adaptation to environmental stress requires coordination between stress-defense programs and cell cycle progression. The immediate response to many stressors has been well characterized, but how cells survive in challenging environments long term is unknown. Here, we investigate the role of the stress-activated phosphatase calcineurin (CN) in adaptation to chronic CaCl stress in We find that prolonged exposure to CaCl impairs mitochondrial function and demonstrate that cells respond to this stressor using two CN-dependent mechanisms-one that requires the downstream transcription factor Crz1 and another that is Crz1 independent. Our data indicate that CN maintains cellular fitness by promoting cell cycle progression and preventing CaCl -induced cell death. When Crz1 is present, transient CN activation suppresses cell death and promotes adaptation despite high levels of mitochondrial loss. However, in the absence of Crz1, prolonged activation of CN prevents mitochondrial loss and further cell death by upregulating glutathione biosynthesis genes thereby mitigating damage from reactive oxygen species. These findings illustrate how cells maintain long-term fitness during chronic stress and suggest that CN promotes adaptation in challenging environments by multiple mechanisms.